Electric meter.



No. 817,305. PATENTED APR. 10, 1906.

T. DUNCAN. ELECTRIC METER.

APPLICATION FILED JUNE 6, 1904.

Witnesses.- v fnz erttor Ma y Thonzas Juneau 24mm y 4o my invention means are provided for prevent- UNITED sTATEs PATENT onrion.

THQMASDUNCAN, OF LA FAYETTE, INDIANA.

ELECTRIC METER.

Specification of Letters Patent.

Patented April 10, 1906.

ing had to the accompanying drawings, form I O 111%; part of this s ecification.

. y invention re ates to electric meters employingi motor elements that actuate damping-dis s or their equivalents within magnetic fields, whereby the rate of operation of a meter may be suitably retarded. The invention is of service in connection with any form 1 of meter employing such a dampingarrangement and is shown herein in connection with commutated or direct-current meters, and

has for its object the provision of means for maintaining the strength of the permanent magnets that are generally employed to furnish the magnetic fields withm which said damping-disks rotate. I j Ever since the introduction of motor-meters for the measurement of electrical energy said meters have been heir to considerable trouble arising from. the character of the damping-ma ets used, as these dainpin ma nets woudd be likely to vary in strengt an become weaker. This weakening in strength causes the meters to increase speed or run faster, in this way rendering the meters inaccurate and necessitating recalibration to resecure accuracy. This weakening is largely due to the aging of the magnets, as in the process of time sufiicient'lines of forde are likely to become dissipated or diverted magnets are preferably of soft iron and are mig t otherwise leak back to their main path.

from the main magnetic circuit furnished b. the permanent magnet. In accordance wit ing the diversion of lines of force. In acconiplishing this result I provide the permanent magnets with subpoles or polar supplements, one such 'subpole or su plement being preferably provided for eac permanent magnetpole. These additions to the permanent desirably mechanically fixedly united with the permanent magnets; The polar supplements preferably extend beyond the poles pro er and serve to direct lines of force that These olar su plements or subpoles are preferably provi ed upon and are desirably integrally formed with respect to straps or bodies of soft iron that are desirably substantially continuous and within which are contained the permanent magnets, whereby paths are defined for leakage, which paths are thus substantially parallel with the paths defined by the permanent magnets. The subpoles or polar supplements and the straps or bodies of iron in association with the permanent ma nets may assume a variety of forms, as wi 1 be readily understood to those skilled in the art.-

In the accom anyin drawin s, I have illustrated severa embo iments o the invention, in which- Figure 1 is a diagrammatic representation of a meter having damping mechanism as constructed in accordance with the preferred embodiment of the invention. Fig. 2 is a view in direction of arrow a of Fig. 1. Fig. 3 is a side view of a modification of the structure shown in Figs. 1 and 2. Fig. 4 isa side elevation of another modification of the invention. Figs. 5 and 6 are respectively front and side elevations of stillanother modifica-.-

ures.

Fig; 1 illustrates one kind of circuit with whic one form of meter containing my invention may be employed. In this figure there is indicated a source of direct current 1, supplying current over transmission-hnes 2 an 3 to translating means, such as lamps 4. The meter has a current field-winding subdivided into coils 5 5, between which the coils 6 u on a rotating spindle 7 are disposed. The 00' s G'terminate 1n the segments of a commutator 8, upon which rests commutatorbrushes 9 9, that serve to include the coils 6 in bridge of the transmission-mains, whereby rotation proportional to the watts or energy 1s secure The commutator-brushes 9 are included in circuit with a torque-coil 10 and an artificial extraneous resistance 11. The shaft or spindle 7 operates a countin -train 12. .Upon a ortion of each meter-spindle 7 there is provi' ed a damping-disk. 13, that rotates between the poles of a permanent magnet 14 to secure the required reduction in the speed of the meter. Hitherto lines of force have become dissipated at the poles of the permanent magnet, to prevent which result I have associated with these poles polar sup-' plements or subpoles 15 16, that are preferably of soft iron and which preferably extend beyond the poles of the permanent magnet, so as to intercept lines of force that spread from the poles of the permanent magnet and act as a guide for said lines of force back to the main magnetic circuit of the dampingmagnet structure. These poles 15 and 16 are preferably integral parts of the strap 17, that surrounds and incloses the permanent magnet, the construction shown in Fig. 1 being-preferred where the poles 15 and 16 are closely a proached. Fig. 3 shows another form of t e invention.

In Fig. 4 the subpoles 15 and 16 are brought somewhat close to the 1poles of the permanent magnet, as is someW at the case in the construction illustrated in Fig. 7. In each construction illustrated in Figs. 1 to 7, inclusive, the front edges of the poles of the permanent magnets are illustrated as facing the subpoles 15 and 16, though this arrangement is not necessarily to be followed, because the construction illustrated in Fig. 8 is highly serviceable. The inclosure 17 1s desirably of soft iron, preferably in' sheet form,

though in Fig. 8 I have illustrated a con-- struction wherein the element 17 may be of cast-iron. The reluctance in the magnetic circuit furnished b the elements 15, 16, and 17 should be so etermined as to prevent such a shortcircuiting of the permanent magnets as to prevent the damping-disks from being subject to a proper amount of flux. This reluctance may be determined in a variety of ways known to those skilled in the art. The elements 17 are desirably in contact'with the permanent magnets and preferably form component parts of the damping-magnet structure, they acting as secondary conductors to lines of force leading from the permanent magnet. i

It is obvious that changes may be made in the various constructions shown without departing from the spirit of my invention, and

do not, therefore, wish to be limited to the precise constructions illustrated; but,

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. An electric meter having a dampingdisk upon its s indle and a damping-magnet inwhose field t e disk rotates, said dampingmagnet including a permanent magnet, and a substantially continuous band of soft iron defining a path for lines of force and within which the permanent magnet is contained, substantially as described.

2. An electric meter having a dampingdisk upon its s indle and a dampin -magnet in whose field t e disk-rotates, said ampingmagnet including a ermanent ma net, and a substantially continuous band efimng a erases path for lines of force and Within which the permanent magnet is contained, substantially as described.

3. An electric meter having a dampingdisk upon its s indle and a dampin -magnet in whose field t e disk rotates, said ampingmagnet comprising a permanent magnet, and an inclosing iron element establishing a portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described. 4. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an iron element establishing a portion of the main fiuxcircuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

5. An electric meter having a dampingdisk upon its s indle and a damping-magnet in whose field t e disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing element of magnetic material establishing a portion of the main flux-circuit parallel to the ortion of the main flux-circuit establishe by the permanent magnet, substantially as described.

6. An electric meter having a dampingdisk upon its s indle and a damping-magnet in whose field t e disk rotates, said damping- ,magnet comprising a permanent magnet, and

an element of magnetic material establishing a portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

a 7. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing element establishing a portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

8. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an element establishing a portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

9. An electric meter having a damping.

disk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing iron element serving to direct and confine leakage lines of force due to the permanent magnet to the main flux-circuit, substantially as described.

10. An electric meter having a dampingdisk upon its s indle and a damping-magnet in Whose field t e disk rotates, said dampingmagnet comprising a permanent magnet, and an iron element serving to direct and confine leakage lines of force due to the permanent magnet to the main flux-circuit, substantially as described.

11. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing element of magnetic material serving to direct and confine leakage lines of force due to the permanent magnet to the main flux-circuit, substantially as described.

12. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an element of magnetic material serving to direct and confine leakage lines of force due to the permanent magnet to the main fluxcircuit, substantially as described.

13. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing element serving to direct and confine leakagelines of force due to the permanent magnet to the main flux-circuit, substantially as described.

'14; An electric meter having a dampingdisk upon its s indle and a damping-magnet in whose field t e disk rotates, said dampingmagnet comprising a permanent magnet, and an element serving to direct and confine leakage lines of force dueto the ermanent ma net to the main flux-circuit, su stantially as escribed.

15. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and an inclosing soft-iron element serving to direct and confine leakage lines of force due to the permanent magnet to the main flux-circuit, substantially as described.

16. An electric meter'having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and

a soft-iron element serving to direct and confine leakage lines of force due to the permanent magnet to the mainfiuX-circuit, substantially as described.

17. An electric meter having a dampingdisk upon its spindle and a damping-magnet in whose field the disk rotates, said dampingmagnet comprising a permanent magnet, and

an inclosing soft-iron element establishing a portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

18. An electric meter having a dampingdisk upon its spindle and a damping-magnet in Whose field the disk rotates, said dampingmagnet com rising a permanent magnet, and a soft-iron e ement substantially coextensive with the permanent magnet and establishinga portion of the main flux-circuit parallel to the portion of the main flux-circuit established by the permanent magnet, substantially as described.

19. A permanent magnet having an inclosing soft-iron element serving to direct and confine leakage lines of force due to the permanent magnet to the main flux-circuit, substantially as described. I

20. A permanent magnet in combination with a substantially continuous band of soft iron defining a path for lines of force and within which the ermanent magnet is contained, substantially as described.

21. A permanent magnet having an inclosing soft-iron element establishing a ortion of the main flux-circuit parallel to t e ortion of the main flux-circuit established by the permanent magnet, substantially as described.

22. A permanent magnet associated with a soft-iron element that is substantially coextensive therewith, substantially as described.

In witness whereof I hereunto subscribe my name this 3d day of June, A. D. 1904.

- THOMAS DUNCAN.

Witnesses:

JOHN E. DALTON, JOHN R. PFROMMER. 

